Elucidation of the gene defect in Marfan syndrome. Success by two complementary research strategies.

Marfan syndrome, which is characterized by manifestations in the skeletal, ocular and cardiovascular systems, is one of the most common inherited connective-tissue disorders. The independently performed genetic assignment of the Marfan locus and classical biochemical and immunohistochemical analyses complemented each other in the search for the Marfan gene defect and in 1991 the fibrillin gene in chromosome 15 was identified as the Marfan gene. So far, three mutations leading to the Marfan phenotype have been reported in this gene coding for a microfibrillar protein. The available data suggests a wide spectrum of different mutations of fibrillin and although mutations of the fibrillin gene account for the majority of Marfan cases, evidence also exists for locus heterogeneity in a minority of Marfan cases.